The index property of the NgFor directive is used to return the zero-based index of the item in each iteration. You can capture the index in a template input variable and use it in the template.
For example, you can capture the index in a variable named indexVar and displays it with the todo's name using ngFor directive as below.
<div *ngFor="let todo of todos; let i=index">{{i + 1}} - {{todo.name}}</div>
